OBTENTION DE TETRAHYDROFURANNES FONCTIONNALISES LORS DE L'ACTION DE REACTIFS ORGANOMETALLIQUES SUR DES γ,δ-EPOXYCETONES

Article abstract of DOI:10.1016/S0022-328X(00)83466-X

The reaction of organolithium and organomagnesium reagents with γ,δ-epoxy ketones affords functionalized tetrahydrofurans by intramolecular cyclisation of an intermediate addition alkoxide.This cyclization is regioselective: the formation of a tetrahydrofuran is always observed while the tetrahydropyran isomer is never obtained.The oxiran ring opening is stereospecific and occurs with inversion of configuration.However, addition of the organometallic reagent to the carbonyl function is of low stereoselctivity and cyclization affords the two cis and trans isomers of the tetrahydrofuran ring in an approximately 1/1 ratio.